Riordinare un array

[Leilond]

<?php
function compare($a, $b) {
       return ($a["size"] > $b["size"]) ? true: false;
}

$arr[0]["name"] = "c";
$arr[0]["size"] = 100;
$arr[1]["name"] = "a";
$arr[1]["size"] = 500;
$arr[2]["name"] = "b";
$arr[2]["size"] = 10;
usort($arr, "compare"); 
print_r($arr);
?>

Oppure

$arr[0]["name"] = "c";
$arr[0]["size"] = 100;
$arr[1]["name"] = "a";
$arr[1]["size"] = 500;
$arr[2]["name"] = "b";
$arr[2]["size"] = 10;

$sortArr = array();
foreach($arr as $elem)
    $sortArr[] = $elem["size"];
array_multisort($sortArr,SORT_ASC,$arr);
print_r($arr);